I'm trying to query a datatable to establish the primary key [identity column], by querying each columns autoincrement property. However its always false (for the column which is the Idenity/PK).
Querying the tables primary key collection reveals that the datatable doesn't think it has a PK.;
Dim dc As DataColumn() = dt.PrimaryKey
Debug.WriteLine(dc.Count) 'Result is 0
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I came across a problem with using a BindingSource as my DataGridViews.DataSource. Whenever I applied a filter to a column in the BindingSource and the user makes changes that don't match the column filter the DataGridViewRows would automatically disappear. A similar thing would happen when applying a Sort to a column. If the user made any changes the DridGirdViewRows would automatically sort causing rows to be moved around. This was not ideal for my application and there isn't anyway to stop this from happening with the BindingSource.
To correct this issue I have to use subsets of data. I use a DataView to apply the filter and sort to the main DataTable, which creates the subset DataTable.The problem is when I use the DataView.ToTable method I loose the Primary Key and RowError information. So I have to reapply this information everytime the user filters or sorts the DataGridView.Is there a better way to get a subset DataTable?[code]...
SELECT
T.TABLE_NAME as TableName,
T.CONSTRAINT_NAME as CONSTRAINT_NAME,
K.COLUMN_NAME as FieldName,
K.ORDINAL_POSITION
FROM
INFORMATION_SCHEMA.TABLE_CONSTRAINTS T
INNER JOIN
INFORMATION_SCHEMA.KEY_COLUMN_USAGE K
ON T.CONSTRAINT_NAME = K.CONSTRAINT_NAME
WHERE
T.CONSTRAINT_TYPE = 'PRIMARY KEY'
AND T.TABLE_NAME = 'mytable'
ORDER BY
T.TABLE_NAME,
K.ORDINAL_POSITION
Query for getting pk of a table. When I Run this query to fill dataset from dataadapter it does not return any value while it returns a row when executed from sql server. Fill method is called correctly as it is working from past 8 months and no problem is yet is there any special property of dataadapter. I also used to put above query in a sp and when try to execute that sp the result was sq not found.
I have imported a single table of a database into a dataset. I would like to find a row containing a specific value and then update some of the data in several columns of that row. When I use the code below, I get this message:"System.Data.MissingPrimaryKeyException: Table doesn't have a primary key."
The first block of code is where I setup my connection and paramters. The updateDB sub is where I want to perform the update. The database was setup in SQL Server. If I have a primary key specified for the database in SQL Server, shouldn't it carry through with the data adapter fill?
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I am new at asp.net, so I would be glad, if anybody could help me in this case... I scanned already the internet for answers, unfortunately with no success..I have a grid view, and this is loaded by a sql data table, this table has 2 keys (RezeptNr and Zutatnr). When I wanna update a row in the data grid, the RowUpdating event fires, so I need to read the Basket Session, what has the complete object stored. I put this in a DataTable (dt1), so far so good..The problem is line: Dim dr As System.Data.DataRow = dt1.Rows.Find(id) Here the compiler alerts, that I have two keys, and he cannot select the data sentence with the find method. I tried it with datatable.select command, that works, but then I have the data sentence in an array, but I need to update the data row of the data table.
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I am importing Tables from a Oracle DataBase, using a VB.NET dataAdapter. I use the "fill" comand to add the imported data to a DataSet. How is it possible to define a specific column of a DataTable as PrimaryKey, after the DataTable is already filled with data?
View 2 RepliesOk so this is going to take some explaining. The process I am trying to do is grab data from a table function in SQL and then fill a dataset with the returned values. I then have to run this query twice more to query an alternative number table. Then add to the same table as the previous queries.This needs to be as fast as possible, so I am currently using an adapter.fill to populate the datasets and then a dataset.merge to put them all into one table.
The problem is the query can return duplicates which waste time and space, because of this I made column 3(part_ID) the primary key to stop duplicates.When this is run with the .merge it quits at the first instance of a duplication and doesn't continue with the population.
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On a client i have an anonymous list containing a multi-column primary key previously selected from the DB.Then i need to select all the records from the DB that equals the primary key list i have stored in the memory.[code]
View 1 RepliesHow i can import row from TABLE1 to TABLE2 without primary keyfield or adding correct value to primary key
i tried with two different codes, but result is same, it says: "In the column "Key"a constraint on the uniqueness.[code]...
I am a complete beginner and I was wondering where do I need to look to learn how to set a file path without knowing if the HDD is C:, D:, E:.. I'm using VB2010
View 5 Replieshow to display the list of all my application users who are currently online on a gridview and every user of my application sees who's online. How do I go about this if and if I am not using the built-in ASP.NET membership controls?
View 4 RepliesHow can i retrieve the key of a hasmap knowing the value?
Example:
'declaring
Dim myHash As New Hashtable
'filling it with some values
[Code]....
Now i want to retrieve the key, lets say of "Z", how i do it?
Did not fount any Method or property to do so.
Dim position as integer = myHash.Item("Z") ' do compile but not work always get position=0 when i expected position=1
If I have four items in the listbox, e.g. a, b, c, d, how can I find the name by knowing from the top the item is number 3 (c)?
View 6 RepliesI need to access Mozilla FireFox's cache, but the path to it is different in each PC. Well, kind of.
This is the path: C:Users%USERPROFILE%AppDataLocalMozillaFirefoxProfiles*.defaultCache"
The ".default" folder will always have that extension, but the asterisk part is different on each PC.[code]...
Given the name of a field that exists on a class (public) and not knowing the field type, is it possible to compare this field on an instance of the class to the same field on another instance of the same class? I'm trying to do this for a "ValueHasChanged" function, something like the following:
Protected Function ValueHasChanged(ByVal fieldName as String) As Boolean
Dim presentFieldInfo = presentInstance.GetType().GetField(fieldName)
Dim originalFieldInfo = originalInstance.GetType().GetField(fieldName)
Return presentFieldInfo.GetValue(presentInstance) <> originalFieldInfo.GetValue(originalInstance)
End Function
The Return line spawns a compiler error about not being able to compare operands of type Object for operator '=', which makes sense, of course. Is there a way I can cast the values or do this differently without having to test the field's type and write a long switch/if...elseif statement?
SPECS: Visual Basic 2008 - SP1/2, Framework 3.0.3.5, Windows XP Pro, SP3? trying to wright code for checking for existing files but what has me stumped is the (WHAT IF PART) of it witch in fact is what I want to see. What im saying is can I find a file without knowing where it is on all drives? Or how can i find a folder if I dont know where they installed it to.
Example: I know that C:Perfect World International <--- is the default location where my game installs but what if I installed it on D:Perfect World International; or rather on drive G or H. How would I test to see if it exist without making a bunch of nested If statements to test every drive for it.
this also applies to files like: D:Perfect World EntertainmentPerfect World Internationalelementelementclient.exe is there a way to find these files to see if they exist. I know that Perfect world international does not use the program files to put there program files in as you see above. so Envirnment variables I think cant be used correct me if I'm wrong. BUT I know the registry of a computer keeps some stord information as to where these applications are installed to like (References App Data).
What I'm trying to do is use this to tell the user in a Label that the game is installed in this path but I know in some circumstances the game is not installed on drive C: or D: or even in this directory some users can install it in there own directory such as C:PWI. and as such the file elementclient.exe can even be in C:PWIelementclient.exe. So to sum it all up can this be found useing some sort of code to find the file and folder and return them both in 2 difrent labels like this
Game Is Installed In: C:Perfect World International
Game Client Name: elementclient.exe, C:Perfect World Internationalelement
Game Found On Drive: C:
ETC.
I'm thinking and keep thinking that this can be done in many ways but as for environment variables I'm stumped. But perhaps windows registry may play a role in doing this but I myself don't even know where this stuff may be found; and even more how to apply it to code.
How can I hide a window knowing his process ID?
I am writing a program which opens another application with the "shell" command (so it's easy for me to get the procID). Once it is running I want to hide or show it when needed by pressing a button in my program...
[code]Now ifrm.document will refer to the parent document.So what is the document INSIDE ifrm?
View 1 RepliesIf document is big then there will be scroll bars in the windows. Does anyone know how to know the measurment of those scroll? For example, if I scroll to look at the bottom domain. Some topscroll or scrolltop property should go up. But which one?
View 2 RepliesI'm creating input radio dynamicly on a ASP.NET page using PlacHolders.
While reader.Read
Dim ltr As New Literal()
Dim ltr1 As New Literal()
[Code]......
how can I get all the items selected on those input radio.
What happens to create the car is the user selects which car he/she wants to create from a combobox and then they press a button to create it.Private Sub btnCreateCar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCreateCar.Click
If cbCarSelect.Text.Contains("Ferrari") Then
c = 1
pictureboxesFerarri(c) = New PictureBox
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I have an application that while running (it doesn't have to have focus, it can be minimized or another window can have focus) can listen and respond to global hot keys pressed. For instance I have the key combo Ctrl+Shift+0. When this hot key is pressed my app can recognize this and then I can do something.
This "something" that I want to do is:
1. Know what window is currently active and has focus when the hot key was pressed. And...
2. Change the size of said window
I can currently identify what window has focus by the following (the code block is inside the function that fires when the hot key is pressed):
Code:
Private Declare Function GetForegroundWindow Lib "user32.dll" () As IntPtr
Private Declare Function GetWindowThreadProcessId Lib "user32.dll" (ByValhwnd As IntPtr, ByRef lpdwProcessID As Integer) As Integer
[Code]....
I can get the handle to the active window and the process that owns that window.
Having this information, how can I get access to the window itself? Furthermore, get access to it's properties so I can change the size of this thing? I'm not sure If this is the right information to be gathering for what I'm trying to accomplish but it seems that I'm close.
Basically I am creating a Windows Service as an 'updater' program to update all my software packages. Whats going to happen is every piece of my software that is installed in its program folder will have an Update.dll this DLL will be a library to do with the update of the software.
There will also be a database in the Updater program folder which will contain a list of all my installed software. So when the service starts it will open my 'database' which will load the paths to all my installed software to a string array. Each path in the string array will have a Update.dll in the folder.
What I need to do then is is in turn call a routine called StartUpdate() from each of those Update.dll which will then do all the work. So the service itself is fairly basic and doesn't really do much I just need to figure out how to access DLL's when I don't actually know what ones will be there while programming, Reason I am doing it this way is to support my future software programmes without having to update the updater.
I am working on a new version of my clipboard manager. I was wondering if there would be a way to copy the value of a given handle without knowing its type? The current methods I know require one person to know the type of the handle (as an example by using Marshal.PtrToStructure).
View 1 RepliesI made a program that is started and running in memory and minimized to the system tray.
When it is first launched it registers global hot keys in windows.These hot keys are used for resizing the current focused window. I'm trying to use it so you can hotkey windows to resize to half the screen, a third of the screen, etc... For instance, if I have two notepads open and notepad 1 is focused and I hit Ctrl+Shift+LeftArrow it will resize notepad1 to the left and half the size of the screen. I have notepad 2 focused and Hit Ctrl+Shift+RightArrow and resize notepad2 to the right side of the screen. So, I can easily see both windows at once.Now, I can successfully get the focused window handle when the hot key is pressed. I'm stuck at this point.
I can use the Windows API call:
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I have a tab control, that the user can add/remove tabs as they please. It is an inventory manager, and the tabs are the departments. Everytime a user adds a department, a new listview is cloned and added to the page. Upon form load, i need it to go through the tab pages, and query the database for items matching the department their in. In other words, if the Department column in the inventory database, matches the Tab Pages text, add it to the listview inside that particular page. I've tried several things, but they all end up buggy. Either it adds them all to the first listview, or it skips every other page, or worse - doesn't add anything at all. Here is the code I have, could anyone help me figure out how to:
Cycle through the pages, if any of the DB's rows Department column matches the tab page text, add it to the listview inside that tab page, then move to the next tab page, and cycle through the DB again. Here is my code, a decent start I believe.
Sub FillList()
Dim incs As Integer
Dim inc As Integer
Dim lst As ListView
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Is there a way to find out if a file exists if you only have the file extension? I tried this but it doesn't seem to work.
If My.Computer.FileSystem.FileExists(drive.Name & "*.cde") Then
This may sound quite basic, but i was wondering how to change the value of a variable in an array, not knowing the index value but knowing what the variable is.
For example, I have an array and I want all strings within it that haven't got a value to say "Stretched". here is what i have tried:
For Each stl As String In Me.stl
If stl = "" Then
stl = "Centered"
End If
Next
My array is called stl(), and the size of it is always changing, so i can't just change the specific variables within the array
Also, is there some way to show/change etc all variables in an array? e.g. msgbox(stl(all))
I know this won't work, but what will?
I eyed VB.NET 2010 Express and created the damn app. It's up and running and it does what it's supposed to do (in v1). Now I'd like to distribute it for free while:
(1). Have a reliable way of knowing (and everybody can check this out) the number of downloads.
(2). The app cannot be passed from one user to another, but has to be downloaded from the reputable biz (there can be more than one biz) that accurately provides the number of downloads.
(3). I can have total control over the app (once it's downloaded by the users), that is if I want to inform the users of updates or whatever, or if I want to add some ad windows to the form I can do it whenever I want and how I please.
How do I do (1) to (3)? What am I supposed to read to do (3)? ADO.NET and ASP.NET? Any shortcut? What's the easiest way of doing it? I'm not sure I'm looking for a career in programming, for now I just want to take this app off my shoulders and go back to daydreaming.
I need to create bitmaps of characters depending on a specified font. When they specify a font, they are specifying:
[Code]....
Knowing this, is it possible to determine the size that a character will be exactly if I know the character and all the information above? I have to draw them to bitmaps that are the same size as the character and no bigger.